The shimano rd 6800 ultegra 11 speed rear derailleur ss produces a simply outstanding shifting motion even on the most stressful extended trips this is all down to the brilliant design that you would expect from shimano the 6800 features a wide outer link that reduces shifting deflection and pivot joint rigidity this ensures that the rear derailleur is not only super accurate in shifting but also provides drivetrain efficiency that you won39t be able to match for